When energy is applied to a skin surface in order to degrade subcutaneous adipose tissue, the energy should preferably reach the underlying adipose tissue layer without damaging the skin surface.
Various types of devices have been used for the treatment of adipose tissue. One popular method of fat treatment is liposuction. This is an invasive procedure involving mechanical disruption of the fat and subsequent removal of the resulting debris from the body. The main disadvantage of this method is its invasive character.
U.S. Pat. No. 5,143,063 describes a method for treating adipose tissue based on thermal destruction of fat by exposing adipose tissue to focused microwave or ultrasound waves. The intensity and the focusing of the energy are determined so as to selectively destroy fat cells without damaging the skin or deep tissues.
U.S. Pat. No. 6,113,558 discloses the delivery of high intensity focused ultrasound (HIFU) in pulsed mode for the treatment of such tissues as cancer tissues and blood clots.
US Published Patent Application US2004/0039312 discloses the application of HIFU for the destruction of adipose tissue. The destruction of the adipose tissue is mainly via hyperthermia.
U.S. Pat. No. 6,607,498 discloses HIFU pulsed to produce cavitation which selectively destroys fat cells.
U.S. Pat. No. 5,725,482 discloses superposition of ultrasound waves from two or more sources to create a wave having a high intensity localized at the adipose tissue to be treated.
U.S. Pat. No. 6,500,141 improves treatment safety with ultrasound by shaping the skin surface using suction.
U.S. Pat. No. 4,958,639 discloses destruction of calculi in the kidney using shock waves.